Work-centering attachment for lathes.



No. 785,193. PATENTED MAR. 21,19O5.,

J. .M. BROWN.

WORK GBNTERING ATTACHMENT FOR LATEX-3S. APPLIGATION FILED APR.29,1904.

, S Witnesses NITED STATES Patented March 21, 1905.

PATENT OFFICE.

WORK-CENTERING ATTACHMENT FOR LATHES.

SPECIFICATION forming part of Letters Patent No. 785,193, dated March21, 1905.

Application filed April 29, 1904:. Serial No. 205,596-

To all whom, it may concern:

Be it known that I, J AMES M. BROWN, a citi- .zen of the United States,residing at Southbend, in the county of Pacific and State of Washington,have invented a new and useful VVork-Centering Attachment for Lathes, ofwhich the following is a specification.

This invention relates to work-centering attachments for wood-turninglathes. I

As is well known to operators of wood-turning lathes, when the stick isof considerable length there is a tendency for the stick to yield underthe pressure of the turning-tool and be thrown out of alinement, causinga loss of time in the turning operation and increasing the difficulty ofsecuring satisfactory results. Various means have been employed tosupport the middle portion of long sticks in lathes in order to overcomethe tendency mentioned; but for the most part the devices employed forthis purpose are not adapted for use with sticks of diiferent sizes, anda considerable delay is occasioned in introducing the stick into theguide.

The object of the present invention is to provide a simple deviceadapted for attachment to a lathe-bed by which diflerent-sized sticksmay be so supported as to overcome the tendency to disalinement andwhich may be brought into operative engagement with a stick Withoutappreciable loss of time.

A further object of the invention is to provide a device of thecharacter specified which may be positively set to hold a stick ofcertain size and which will effectively support the stick withoutbinding or otherwise interfering with the rotation of the stick inthe'lathe.

In describing the invention reference will be had to the accompanyingdrawings, in

which is illustrated the preferred form of em-,

bodiment of the invention, it being understood that changes in the form,proportions, and exact mode of assemblage of the elements exhibited maybe resorted to Without departing from the spirit of the invention orsacrificing its advantages.

In the drawings, Figure 1 is a view in side elevation of a lathe-bed andthe head and tail stocks mounted thereon, with a stick supported betweensaid stocks and secured intermediate of its ends by means of anattachment constructed in accord with the present invention. Fig. 2 is atransverse section through the lathe-bed with the attachment shown inoperative position. Fig. 3 is a view also in transverse sectionthroughthe lathe-bed, showing the jaws of the attachment open for the receptionof the stick. Fig. 4 is a detail view of a nest of face-pieces orguide-blocks to be employed on the jaws of the attachment. Fig. 5 is aview showing a set of face-blocks of modified form. Fig. 6 is a detailview showing a mode of supporting face-blocks on the jaws on theattachment. Fig. 7 is a detail perspective view showing aslightly-modified form of jaw. Fig. 8 is a perspective detail view of aslightly-modified form of face-block.

Referring to the drawings, in which corresponding parts are designatedbysimilar characters of reference; B designates the bed of an ordinarywood-turning lathe, and H and T designate the head and tail stocks,respectively. Work in the form of a stick S is rotatably supportedbetween the head and tail stocks in the usual manner and the turningoperation is effected by means of turning-tools of any preferredcharacter.

The attachment proper comprises a pair of jaws 1 1, both pivoted at 2upon an angular frame 3, comprising a horizontal arm i and a verticalarm 5. The frame 3 is secured by means of a clamp-bolt 6 at any desiredpoint upon the bed or shears of the lathe and will ordinarily be fixedin position about midway between the head and tail stocks of the lathe.The two jaws 1 1 are provided near their free ends withoppositely-arranged concavities 7 in which may be placed concave blocks8, 9, and 10 to correspond to sticks of difierent sizes. The two jawsare longitudinally slotted at 11 and 12, respectively, and a lever 13,provided with pins 14sand 15 for engagement with the slots 11 and 12, ismounted upon a pivot 16 between the two jaws in order to afford meansfor approximating and separating the jaws when desired. The lever 13 isso arranged that the free or handle end projects upward and is providednear its extremity with a lip .17 for engagement with the notches 18 ofa rack 19, secured upon the vertical arm 5 of the frame 3. The lever 13is made of iron, as are the jaws 1 l, and is sufliciently resilient topermit the lip thereon to be readily moved into and out of engagementwith the notches of the rack 19, so that the jaws may be quickly broughttogether or separated, as desired.

In use the attachment will be set in proper.

position relative to the head and tail stocks of the lathe and the jawswill be spread apart, as shown in Fig. 3, when the stick is introducedinto the lathe. The stick having been centered properly, the two jawswith their concavities provided with face-blocks, if necessary, will beapproximated by means of the lever 13 until the free ends of the jawsare in such close proximity to the stick that any appreciable lateralplay thereof will be impossible. The jaws will then be secured in thisposition by bringing the lip on the lever into engagement with theadjacent notch in the rack 19, and the turning operation may then bebegun.

As most long-turned formssuch as porchcolumns,balusters,and the likearegenerally made in standard sizes in woodworking plants, the face-blocks8, 9, and 10 may be made of such size that the number required for usein the production of any particular piece of work may be determinedinstantly and the necessity of experimenting to determine the propernumber avoided. The most common sizes for porch-columns are those ofthree and threeeighths, four and three-eighths, and five andthree-eighths inches in diameter, and the faceblocks illustrated aredesigned for use in turning porch-columns of this size. With face-blocksof the form shown it will be necessary, when it is desired to turncolumns of the smaller sizes, to use a plurality of faceblocks in theconcavity of each jaw; but, if desired, face-blocks of the form shown at20, 21, and 22 may be used instead. The modified form of face-blocksdiffers from the form first mentioned in that each block has its outersurface provided with a dovetailed groove 23, adapted to engage flanges2 1 on the jaws. In order to obviate the employment of any holdingmeanssuch as bolts or screws for retaining the face-blocks positionedupon the jawsthe groove, in addition to being dovetailed, is tapered,being approximately wedgeshaped when viewed in plan, and the flanges 24are similarly tapered or wedge-shaped,

and by this arrangement when the face-block is positioned upon the jawit will be positively held from accidental separation therefrom byreason of the frictional contact between the edges of the flanges andthe inner walls of the groove. By preference, the pitch or inclinationof the flanges of the two jaws are in opposite directionsthat is to say,the narrow ends of the flanges on the lower jaw are at its terminal andthe wide ends of the flanges on the upper jaw are at the like terminal.This arrangement is advantageous in positioning the face-blocks, and,moreover, by the manner of thus arranging the flanges on the upper jawthe face-block cannot become accidentally disconnected from its jaw byworking off at the end.

In order to adapt the device for use in connection with lathes ofdifferent sizes, the frame 3 is provided with a plurality of orifices25, to be engaged by the pivot 2 of the jaws, and by this means the jawscan be raised or lowered to bring the face-blocks in the properoperative relation with the work. Of course in adjusting the jaws itwill be necessary to change the pivotal point of the lever 13, and toeffect this the frame is provided with a second series of orifices 26,corresponding in number to the series of orifices 25, and the frifices26 are engaged by the pivot 16 of the ever.

By using blocks of the modified form shown in Fig. 5 the necessity ofusing more than one face-block on each jaw at any time will be obviated;but the single blocks for forms of the smaller sizes will be heavierthan the blocks for the smaller sizes of the form first described.

From the foregoing description and the drawings illustrative thereof itwill be seen that sticks of difl erent sizes may be convenientlysupported in a lathe, so that the middle portions thereof will not bethrown out of alinement by the pressure of the turning-tool, and it willalso be seen that the time required for bringing the jaws of the guideinto operative relation with a stick in the lathe is so slight as to benegligible.

Having thus described the construction and operation of my invention,whatI claim as new, and desire to secure by Letters Patent, is-

1. A work-centering attachment for lathes comprising a standard adaptedfor connection with the bed of a lathe and provided with two series ofspaced openings, apair of guide members pivotally connected by a pinthat engages one of the series of openings, and a lever operativelyconnected with the guide members and having its fulcrum adapted toengage other series of openings.

2. A Work-centering attachment for lathes comprising a standard adaptedfor connection with the bed of a lathe, a pair of jaws carried by thestandard and having oppositely-disposed concaved faces provided withlateral flanges, and face-blocks having grooves to engage the flanges.

3. A work-centering attachment for lathes comprising a standard adaptedfor connection with the bed of a lathe, a pair of work-supporting jawsmounted thereon and having oppositely-disposed concaved faces providedwith lateral angularly-disposed flanges, and face-blocks having groovescorresponding in contour to the flanges.

lIO

4. A work-cen tering attachment for lathes crum adapted to engage theother series of I comprising a standard adapted for connection openings.with the bed of a lathe and provided with two In testimony that I claimthe foregoing as series of spaced openings, a pair of guide memmy own Ihave hereto afliXed my signature in hers connected at one end by a pinthat engages the presence of two witnesses. Y

one of the series of openings, detachable space- JAMES M. BROWN. blockscombined with the other ends of the Witnesses: members, and a leveroperatively connected J. H. DALTON,

with the guide members and having its full V A. P. LEONORD.

